If you do want to use two separate chart areas, create a new chart area in the Chart's ChartAreas collection, then set the Series.ChartArea property on each series to the name of the appropriate chart area.

The poster wanted to combine a StackedBar and a line chart. Your example shows a StackedColumn. When you try to combine a StackedBar and Line, it complains that they are not compatible.

Can I somehow 'rotate' the line chart to line up with my bars? My dilemma is that I have up to 100 rows in my data to chart and if I try to display them as columns, I run out of room. If I display them as rows, the chart will scale a bit better.

It's a perfectly good point that the poster asked for "stacked bars" combined with a line, but typically clients don't share the terminology that Dundas Chart uses--when someone says they want a "bar" chart, they usually mean vertical bars, which is known as the Column chart type in Dundas Chart. I didn't mean to make that assumption though.

The Bar, StackedBar and Gantt chart types have their axes reversed, so that the X axis is on the left and the Y axis is on the bottom. This makes the Bar chart types and the Line chart type incompatible, because the "value" (Y) axes do not match up and it theoretically does not make sense to combine these two chart types. The X axis works very differently from the Y axis, and the Y axis of the bar chart cannot be the same as the X axis of the line chart.

If you do want to truly combine these two chart types, it is still possible in Dundas Chart. To start with, the two series with the different chart types need to be assigned to different chart areas:

You may also need to manually set the chart areas' InnerPlotPosition in the same way. (This can all be done at design-time rather than in code, of course.) It would be up to you, though, how to handle which of the chart areas' axes should be visible and which should be hidden. As mentioned, the two series cannot share the same axis.